Some malware infect your USB keys by creating an autorun.inf file on it. So when you insert this USB pen disk in another clean computer, that computer is also infected. You can immunize the USB disks and your computer by using a freeware tool from Panda Security Labs – called Panda USB Vaccine. The Panda USB Vaccine supports Windows XP, Vista, 7 and 8.
You can download Panda USB Vaccine from Panda Security Lab’s web site. Double click on the setup file to install the Panda USB Vaccine. During the setup you are presented with a configuration screen. Do no choose the NTFS Support as it is still in beta experimental state. If you choose the Automatically vaccinate any new inserted USB key option, then all the non-vaccinated USB disks you insert will be auto-vaccinated (read about this later in the article).
When you launch the Panda USB Vaccine, you see a screen similar to the shown below. To vaccinate your computer you can click on Vaccinate Computer button. This would disable execution of autorun.inf files on your computer when you insert any kind of removable disks like a CD, DVD or USB disk.
You can also select a removable USB disk from the drop down list and click on Vaccinate USB to vaccinate it. This would create a permanent autorun.inf file on that USB drive so that a virus cannot overwrite it – disabling the autorun.inf on that USB drive.
If you insert a non-vaccinated USB disk in your computer while the Panda USB Vaccine is running, a dialog window offering to vaccinate the USB drive is shown. You can choose the vaccinate the inserted USB disk. Had you chosen the auto-vaccinate option in the setup, all the newly inserted USB disks will be automatically vaccinated.
If you did not install Panda USB Vaccine with these options for auto-vaccination, you can just re-run the setup program and install it again with new options.
You can also use the command line options with Panda USB Vaccine. To use the command line, you have to open an elevated command prompt window in Windows Vista, 7 and 8. You must be running as an administrator in Windows XP to open the command prompt with required access. In the command prompt, you have to change directory to the Panda USB Vaccine by giving the command cd %programfiles%Panda USB Vaccine
Once you have changed the directory, you can give the following command to vaccinate a USB disk in drive F: by giving the command USBVaccine F. If you want to vaccinate your computer, you can give the command USBVaccine +system. To remove vaccination from your computer, you can give the command USBVaccine -system.
You can download Panda USB Vaccine from http://acs.pandasoftware.com.